1. Field
Apparatuses and methods consistent with exemplary embodiments related to adjusting an aperture through which light is transmitted using a microelectrofluidic method.
2. Description of the Related Art
Devices, such as aperture diaphragms or shutters, for adjusting and controlling light transmittance, are used in apparatuses for capturing images, or in image display apparatuses in order to drive pixels.
A related art variable aperture diaphragm operates a plurality of metal blades; however, mechanical movement, frictional force, and usage of movable mechanical components are obstacles in reducing a size of the optical system.
A micro-electromechanical system (MEMS) aperture diaphragm of an electrothermal type or an electrostatic type has been suggested; however, drawbacks are that the aperture is non-circular, there is a gap between blades, and the largest aperture ratio with respect to an entire device area is 1% or less.
On the other hand, since optofluidic technology combining micro-optics and microfluidics has been developed, a variable aperture diaphragm that adjusts an aperture ratio by transforming a poly-dimethylsiloxane (PDMS) membrane using air pressure has been suggested. The resolution of the variable aperture diaphragm may be improved using a three-dimensional (3D) structure and a capillary force. The variable aperture diaphragm has a higher aperture ratio than that of the MEMS aperture diaphragm; however, a syringe pump has to be used to drive the variable aperture diaphragm.
In addition, an aperture diaphragm using a liquid lens operated by a dielectric force has been recently suggested, and an aperture ratio of the aperture diaphragm may be adjusted only by electric wires formed at a bottom of the aperture without using an external driving pump.